CARPOLOGICAL MATERIAL AS AN INDICATOR FEN PEATLANDS DEGRADATION

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1 POLISH JOURNAL OF NATURAL SCIENCES Abbrev.: Pol. J. Natur. Sc., Vol 32(4): , Y CARPOLOGICAL MATERIAL AS AN INDICATOR FEN PEATLANDS DEGRADATION Department of Botany and Plant Ecology Wrocław University of Environmental and Life Sciences, Poland K e y w o r d s: degraded fen peatland ecosystems, plant macroremains, fruits and seeds of non peat-forming plant species, western Poland. Abstract The abandonment of agricultural use of drained fen peatlands contributes to intensified moorshing process and, consequently, faster of wetlands areas degradation. Peat mineralization causes the eutrophication of the habitat which, along with changing humidity, enables the presence of so-called non peat-forming plants. Among the seeds and fruit present in the top layer of degraded marshy soils, there may also be carpological material originating from non peat-forming plants. 12 soil profiles from selected post-marsh meadows in western Poland were the subject of this study. The studies found seeds and fruit of 69 plant species in moorsh layers, 42 of which were peat-forming species but as many as 27 were non peat-forming plants. Of the latter the most common were, among others, Juncus effusus and Juncus conglomeratus, Urtica dioica, which were characterized by the highest quantitativeness of fruit and seeds. Among the recorded non peat-forming species almost 50% belonged to Molinio-Arrhenatheretea class, which means they were species connected with semi-natural and anthropogenic meadows occurring on mineral or organic-mineral soils but also characteristic of muck emerging from degraded fen peatlands. Peat-forming species belonged to Phragmitetea and Scheuchzerio-Caricetea nigrae classes. Studies showed that the set of fruit and seeds of non peat-forming plants found in the upper layers of peat deposit was not dependent on the thickness or type of peat from which the moorsh originated, nor was it dependent on geographical location. Address: Katarzyna Kołodziejczyk-Prażmo, Wrocław University of Environmental and Life Sciences, pl. Grunwaldzki 24a, Wrocław, Poland, katarzyna.kolodziejczyk84@gmail.com

2 696 MATERIAŁ KARPOLOGICZNY JAKO WSKAŹNIK PROCESU DEGRADACJI TORFOWISK NISKICH Katarzyna Kolodziejczyk-Prażmo, Klara Tomaszewska Katedra Botaniki i Ekologii Roślin Uniwersytet Przyrodniczy we Wrocławiu, Polska S ł o w a k l u c z o w e: zdegradowane torfowiska niskie, makroszczątki roślinne, owoce i nasiona nietorfotwórczych gatunków roślin, zachodnia Polska. Abstrakt Zaprzestanie użytkowania rolniczego odwodnionych torfowisk niskich przyczynia się do zwiększenia intensywności procesu murszenia torfu, a tym samym szybszej degradacji siedlisk bagiennych. Mineralizacja torfu powoduje eutrofizację siedliska, co wraz ze zmianą stopnia uwilgotnienia umożliwia wkraczanie tzw. nietorfotwórczych gatunków roślin. Wśród nasion i owoców znajdujących się w stropowej warstwie zdegradowanej gleby bagiennej może pojawiać się również materiał karpologiczny pochodzący od gatunków nietorfotwórczych. Przedmiotem badań było 12 profili torfowych pochodzących z wybranych łąk pobagiennych znajdujących się w zachodniej Polsce. W trakcie analiz w warstwach murszu rozpoznano nasiona i owoce 69 gatunków roślin, z czego 42 stanowiły gatunki roślin torfotwórczych, a aż 27 gatunki roślin nietorfotwórczych. Najczęściej odnotowywanymi gatunkami nietorfotwórczymi były m.in.: Juncus effusus i Juncus conglomeratus oraz Urtica dioica, które charakteryzowały się jednoczenie największą liczebnością owoców i nasion. Wśród rozpoznanych gatunków nietorfotwórczych prawie 50% stanowili przedstawiciele klasy Molinio-Arrhenatheretea, czyli gatunki związane z półnaturalnymi i antropogenicznymi zbiorowiskami łąkowymi występującymi na glebach mineralnych lub organiczno-mineralnych i charakterystycznych także dla murszy wytworzonych z torfu niskiego. Gatunki torfotwórcze były zaś reprezentowane głównie przez przedstawicieli klasy Phragmitetea i Scheuchzerio-Caricetea nigrae. W badaniach wykazano, że zestaw nasion i owoców gatunków roślin nietorfotwórczych, odnalezionych w wierzchnich warstwach złóż torfowych, nie był zależny od miąższości warstwy murszu oraz rodzaju torfu, z którego powstał mursz, jak również od położenia geograficznego obiektu. Introduction Wetland and marshy meadows play a significant role in the rural landscape of Poland, even though they only constitute 10% of hydrogenic habitats (DEMBEK 2002). They are, however, and similarly to active peatlands, endangered by human activity. Agricultural use of peatlands caused the drying out of hydrogenic habitats. Political and economic changes in Poland at the end of the XX century led to the abandonment of many wetland meadows. It is now known that the abandonment of drained wetland meadows leads to intense degradation of peat soil through ever deeper moorhing process (BRANDYK et al. 2007, DEMBEKA and PIÓRKOWSKI 2007, ILNICKI and SZAJDAK 2016). As a result, the thickness of peat decreases and, eventually, disappears. Consequently, on

3 Carpological material as an indicator over 80% of Polish peatlands the peat-forming process disappear (GROOTJANS and WOŁEJKO 2007). The proceeding mineralization of peat changes habitat conditions, which makes it possible for non peat-forming plant species to occur (KRYSZAK et al. 2004, KUCHARSKI 2008, TOMASZEWSKA et al. 2011). A proper evaluation of the dangers to peatlands is only possible when it is based on complex studies of particular sites (DOBROWOLSKI et. al. 1998). A set of research and diagnostic tools of wetlands needs to be used. From the botanical point of view, the study needs not only the characteristics of plants presently occurring in the peatlands but also a historical approach to their development. The stratigraphic analysis is one of the most important paleobotanic methods revealing the genesis of a peatland. Plant macroremains analysis is divided into two parts: reproductive (seeds and fruit) and vegetative structures. Seeds and plants in peat soil form a rich seed-bank, with regard to both the degraded layer and the unchanged peat deposit. Therefore, it could be assumed that floristic changes occurring on marshy meadow surface should also be reflected in the macroremains composition occurring in the mineralized fen layer, namely the moorsh. Consequently, it seems more prudent to analyze peat deposits including both the unchanged and the degraded part (KLIM- KOWSKA 2006, KOŁODZIEJCZYK and TOMASZEWSKA 2010). The depth of non peat-forming seed and fruit occurrence could indicate the thickness of the degraded peat soil moorshing process. The aim of the research is to establish a list of indicator plant species whose carpological material (seeds and fruit) found in the upper layers of peat deposits could inform us about the steps of the mineralization (moorshing process) of peatlands and, at the same time, about its degradation. Materials and Methods Seven meadows located on fen peatlands in Poland were selected for the study (Table 1). The sites were selected using the following criteria: post-marsh meadows on fen peatlands used for agriculture in the past or unused for over a decade; the thickness of peat layer should exceed 1m, as both the degraded and the unchanged part of the deposits were to be studied; the studied sites should be located in various parts of western Poland. 12 soil profiles were collected using an Instorf type drill with canister diameter of 5 cm and height of 50 cm. The material for studies was both moorsh in the upper part of the peat profiles and peat occurring in lower parts. In the laboratory the collected profiles were divided into 5 cm parts (around 20 cm 3 of volume), which were then samples for stratigraphic analyses. The paleobotanic research included the following:

4 698 Study sites location and usage Table 1 Name of peatland Voivodeship Name of profiles Geographical location Usage Miękinia Lower Silesian Voivodeship Miękinia N51 o , secondary paludification E16 o Koskowice Lower Silesian Voivodeship Koskowice N51 o , E16 o Milicz Lower Silesian Voivodeship Milicz 1 N51 o , E17 o Milicz 2 N 51 o , E17 o Milicz 3 N51 o , E17 o Borek Opole Voivodeship Borek 1 N51 o , E18 o Borek 2 N51 o , E18 o Czarnocin West Pomeranian Voivodeship Czarnocin N53 o , E14 o Widzieńsko West Pomeranian Voivodeship Widzieńsko N53 o , E14 o Kikorze West Pomeranian Voivodeship Kikorze 1 N53 o , E15 o Kikorze 2 N53 o , E15 o Kikorze 3 N53 o , E15 o used meadow unused grassland pasture 1. determining the ash content in peat through burning 1/5 of each section in a muffle furnace at 600 o C for 4 hours ash content was determined in accordance with Polish Norm (Torf i wyroby... PN-G-04596). 2. determining the botanical content of peat the samples were placed in 10% NaOH solution and later rinsed under water on a sieve with 0,3 mm meshes. The rinsed plant remains were segregated under a stereoscope microscope into vegetative structures and seeds/fruit. Carpological material was of particular significance. Atlases and other sources were used to identify the remains, among others the following: BERGGREN (1969), KATZ et al. (1965, 1977), GROSSE-BRAUCKMANN (1972, 1974) GROSSE-BRAUCKMANN, STREITZ (1992), CAPPERS et al. (2012). The types and species of peat were determined on the basis of botanical plant remains in peat in accordance with the system of genetic classification (TOŁPA et al. 1967, PARENT and ILNICKI 2002) and the Polish Norm (Torf. Genetyczny... PN-85/G-02500).

5 Carpological material as an indicator Plant species names were taken from MIREK et al. (2002). Classifying particular species into particular phytosociological classes was based on the studies by MATUSZKIEWICZ (2002). Results In each of the studied peatlands there was a clearly visible layer with initiated moorshing process. Miękinia location was an exception the whole profile with thickness of only 0.3 m was made of moorsh. In other profiles the degrading marshy soil had thickness between 0.1 m (Widzieńsko, Kikorze 1 and Kikorze 3) to 0.27 m (Milicz 2), while 0.2 m was the most common result (Table 2). These thicknesses were consistent with the extent of levels determined on the basis of higher ash content. The analyses of moorsh layers in the profiles revealed seeds and fruit of 69 plant species, 42 of which were peat-forming plants (belonging to classes Scheuchzerio-Caricetea nigrae and Phragmitetea and occurring in communities characteristic of fen peatlands) and as many as 27 non peat-forming species occurring only in dried out and degraded peatlands (Table 3). The analyses also showed fruit fragments impossible to fully identify, belonging to Potentilla genus and Asteraceae family. Table 2 Peat species occurring under the moorsh layer along with the number of species indicating the moorshing process and the number of peat-forming species found in muck layers of the studied profiles Number of species Moorsh layer Profile Peat species under the moorsh layer indicating the [m] moorshing process Number of peat- -forming species in moorsh layer Miękinia 0.30 only moorsh 1 9 Koskowice 0.20 sedge peat 7 7 Milicz sedge peat 7 8 Milicz sedge peat 7 11 Milicz sedge peat Borek sedge peat 3 6 Borek sedge-moos peat 2 6 Czarnocin 0.20 sedge peat 2 6 Widzieńsko 0.10 sedge peat 3 8 Kikorze Drepanocladus moos (Drepanocladus) peat 5 4 Kikorze Drepanocladus moos (Drepanocladus) peat 7 10 Kikorze Drepanocladus moos (Drepanocladus) peat 4 6

6 700 Table 3 The index of plants indicating the decaying process in peat along with the number of occurrences of a given species and the number of seeds/fruits in the moorsh layers of the studied peat profiles Species Phytosociological classes Number of occurrences in 12 profiles Number of seeds/fruit in moorsh layers Agrostis gigantea Roth Mol.-Arrh. 1 5 Alopecurus pratensis L. Mol.-Arrh. 1 8 Anthoxanthum odoratum L. Koel 1 70 Calamagrostis epigejos (L.) Roth Epilob. ang. 1 1 Cisrium palustre (L.) Scop. Mol.-Arrh Geranium palustre L. Mol.-Arrh Holcus lanatus L. Mol.-Arrh. 1 1 Hydrocotyle vulgaris L. Scheu.-Car. nigrae Juncus conglomeratus L. Em. Leers Mol.-Arrh Juncus effusus L. Mol.-Arrh Mentha arvensis L Moehringia trinervia (L.) Claivr. Atrem. 1 1 Molinia caerulea (L.) Moench. Mol.-Arrh. 1 8 Polygonum bistorta L. Mol.-Arrh. 1 2 Polygonum lapathifolium L. Bid. trip. 1 1 Potentilla anserina L. Mol.-Arrh Potentilla argentea L. Koel Potentilla erecta L. Nardo-Callun Potentilla sp Ranunculus acris L. Mol.-Arrh Ranunculus repens L. Mol.-Arrh Ranunculus sceleratus L. Bid. trip Stellaria holostea L. Quer.-Fag. 1 5 Trifolium repens L. Mol.-Arrh Urtica dioica L. Artem Viola arvensis Murray Stell. med. 3 1 Others from Asteraceae 3 1 Class names: Mol.-Arrh. Molinio-Arrhenatheretea, Epilob. ang. Epilobietea angustifolii, Scheu- Car. nigrae Scheuchzerio-Caricetea nigrae, Atrem Artemisietea, Bid. trip. Bidentetea tripartiti, Nardo-Callun Nardo-Callunetea, Quer.-Fag. Querco-Fagetea, Stell. med. Stellarietea mediae, Koel. Koelerio glaucae-corynephoretea canescentis. The fruit and seeds most clearly indicating the moorshing process belong to Juncus conglomeratus and Juncus effusus (recorded in 12 profiles) and Urtica dioica (occurred 6 times). The number of sporomorphs of these species in the moorsh layers was varied, but sometimes very high (Table 3). For instance,

7 Carpological material as an indicator Fig. 1. The percentage of phytosociological classes of non peat-forming seeds and fruits plant species recorded in the degraded layers of all analyzed peat profiles the profile Borek 1 had 137 fruits of Urtica dioica, whereas the profile Milicz 3 had 853 seeds of Juncus conglomeratus (Table 3) The carpological material of other non peat-forming plant species occurred less often, e. g. Potentilla anserina was recorded 3 times, Ranunculus sceleratus and R. acris 4 times, and Polygonum bistorta only once. In profiles Kikorze 2, Milicz 1, Milicz 2 and Milicz 3 Hydrocotyle vulgaris was recorded. The species does belong to the Scheuchzerio-Caricetea nigrae class, but in Polish fen peatlands it is a sign about the initiation of peat drying out in the upper layers of peat deposit. The recorded seeds and fruit may also indicate the earlier was fen peatlands were used. Consequently, seeds of Trifolium repens (Koskowice, Milicz 2, Milicz 3) and fruit of Alopecurus pratensis (Borek 2), Anthoxanthum odoratum (Kikorze 2) and Holcus lanatus (Milicz 3) confirm previous peatland usage as meadows. In all profiles, in the moorsh layer, the study recorded a mosaic of seeds and fruit of peat-forming and non peat-forming species. However, in each location there was a different combination and a different number of species of both groups (Table 3). Research suggests that geographical location and peat type from which moorsh originates do not influence the composition or number of non peat-forming species. (Table 2, Table 3). Similarly, on the amount of seeds and fruit of particular plant species.

8 702 Non peat-forming plant species, whose seeds and fruit were noted in moorsh layers belong to 9 phytosociological classes (Figure 1). Molinio-Arrhenatheretea class was the most numerous with 13 species (48,1% of 27 species). Species belonging to this class are connected with semi-natural and anthropogenic grassland communities occurring on mineral or organic-mineral soils and also characteristic of moorsh originating from fen peatlands (MATUSZKIEWICZ 2002, DIERSSEN K. and DIERSSEN B. 2008). The other classes are presented to a lesser extent (Figure 1). The research suggests that all 27 species (Table 3) can be seen as indicative of peat decay process. Discussion The obtained results are confirmed by previous studies. While describing Rabinówka peatland, DRZYMULSKA (2004) recorded the presence of Urtica dioica, Ranunculus acris and several fruit of species from Asteraceae family in the decaying surface layer of the peat deposit. Similarly, the peatland near Pasikurowice (Lower Silesia) had seeds of Juncus effusus and fruits of Urtica dioica in the upper layer of decaying peat (MALKIEWICZ et al. 2015), and the latter was more numerous 31 fruits. In Równina Wełtyńska (north-western Poland, near Czarnowo) there is a peatland with visible degenaration of peat-forming communities. The changes are a reflection of an ongoing moorshing process. The upper 0,1m had seeds of Juncus effusus and fruits of Ranunculus acris (MALKIEWICZ and TOMASZEWSKA 2009) An even higher number of non peat-forming species was recorded in upper layers of Większyce peatland (Opole Voivodeship) (TOMASZEW- SKA 2012) with seeds/fruit of Urtica dioica, Ranunculus repens, Stellaria holostea, Juncus effusus and Trifolium repens. The presence of Triforium repens suggests previous usage of the peatland as a meadow. Urtica dioica fruit are a particularly significant indicator. It is a nitrophilous species and its presence suggests a heightened content of nitrogen in the soil. In the case of fen peatlands a higher concentration of this element is a result of peat mineralization (moorshing process), and the process occurrs during drying out the surface layers of peat deposits (GOTKIEWICZ 1987, 2007; TURBIAK and MIATKOWSKI 2006). Conclusions 1. The moorsh layer of the studied profiles had seeds and fruit of 69 plant species, of which 42 species are peat-forming and 27 are non peat-forming species occurring on degraded and dried out peatlands.

9 Carpological material as an indicator The presence of Urtica dioica fruits and/or Juncus effusus and J. conglomeratus seedsisanimportantindicatorofanongoingdecayingprocess. 3. The presence of Triforium repens seeds and Alopecurus pratensis, Anthoxanthum odoratum caryopses is an indicator of previous peatland usage as meadows. 4. The recorded non peat-forming species belong to 9 phytosociological classes, of which Molinio-Arrhenatheretea is the most numerous. 5. Each of the dried peatlands has its own composition of non peat-forming species, whose seeds or fruit are present in the moorsh layer. 6. The composition and number of non peat-forming species recorded in the moorsh layer of particular sites is not connected with the peat type, from which the moorsh originates and geographical location of peatland. The same lack of dependency occurs with regard to the number of seeds and fruit of particular plant species. 7. The presence of seeds or fruit of any of the recorded 27 non peat-forming plant species is always an indicator of the degradation in the upper layers of peat deposits. Translated by JACEK JABŁOŃSKI Accepted for print References BERGGREN G Atlas of seeds and small fruits of Northwest European plant species with morphological description. Part 2. Cyperaceae. Swedish Natural Science Research Council, Stockholm, pp. 88. BRANDYK T., GNATOWSKI T., OLESZCZUK L., SZATYŁOWICZ J., SZEJBA D Postęp w badaniach właściwości fizycznych gleb torfowo-murszowych. In: Torfowiska i mokradła. Wyd. SGGW, Warszawa, pp CAPPERS R.T.J., BEKKER RM., JANS J.E.A Digitale Zadenatlas van Nederland. Digital seed atlas of the Netherlands. Barkhuis Publishing & Groningen University Library, Groningen, XXVI. DEMBEK W Aktualne problemy mokradeł. Walory przyrodnicze mokradeł a ich rolnicze użytkowanie. Woda-Środowisko-Obszary Wiejskie. Rozprawy Naukowe i Monografie, 4: DEMBEK W., PIÓRKOWSKI H Mokradła w krajobrazie Polski. In: Torfowiska i mokradła. Wyd. SGGW, Warszawa, pp DIERSSEN K., DIERSSEN B Moore. Verlag Eugen Ulmer. Stuttgart, pp DOBROWOLSKI K., HALBA R., LEWANDOWSKI K Przegląd środowisk wodnych i błotnych w Polsce. In: Ochrona środowiska wodnych i błotnych w Polsce. Eds. K. Dobrowolski, K. Lewandowska. Oficyna Wydawnicza Instytutu Ekologii PAN, pp DRZYMULSKA D History of vegetation at Rabinówka mire (Gródek-Michałowo depression, NE Poland). In: The future of Polish mires. Societatis Scientiarum Stetinensis, Agricultural University of Szczecin, Szczecin, pp GOTKIEWICZ J Mineralizacja organicznych związków azotowych w glebach torfowo-murszowych wieloletnich doswiadczeń. Bibl. Wiad. IMUZ, 68: GOTKIEWICZ J Azot i fosfor w glebach hydrogenicznych. In: Torfowiska i mokradła. Ed. E. Biernacka. Wydawnictwo SGGW, Warszawa, pp

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